Towed submersible transducers for sonar have usually been of a configuration largely defined by the function of the sonar equipment itself with hydrodynamic consideration secondary. Another configuration which has been used involves a somewhat streamlined projectlie shape with a center of gravity near one end and a large diameter shroud carrying receiving hydrophones attached through a swivel arrangement at the other end to act as a stabilizing tail. Recently there has been a requirement for a 360.degree. scanning sonar which is to be towed from a helicopter or from a vessel. Conventional hydrodynamics indicated that a good approach would be to make a somewhat streamlined vehicle with control surfaces supporting an exposed rotatable transducer. This was considered not satisfactory because the transducer and extended parts of the towed body were vulnerable to rough handling on decks of ships and from helicopters, etc. Another approach was to build a sonar into a somewhat streamlined housing but to retain the fins or control surfaces. This approach, although certainly operative, is subject to some of the same dangers of exposure to damage from rough handling and is also somewhat unsatisfactory because of the limited volume which is normally accommodated within such a housing. Alternatively, if the housing is made larger, then the control surfaces extend outwardly such that the overall dimensions make the transducer awkward to handle. There is, therefore, a need for a towed submersible body configuration capable of housing a scanning sonar system or other underwater instrumentation with sufficient volume to permit some freedom of movement within the body, which is rugged and provides reasonably good protection for the contents and which may be towed at some significant speed without such instability as would adversely affect operation of the sonar or other instrumentation.